Exposure to a widely used herbicide during the middle months of pregnancy may increase the chance of giving birth too early, before 37 weeks, a new study shows.

The investigation focused on glyphosate, the active chemical ingredient in professional-grade Roundup products, which are sprayed on commercial food crops, like grains and legumes, and on residential gardens. Residues of the chemical have been detected in cereals, snack foods, and fresh fruits and vegetables.

Led by NYU Langone Health researchers, the new study, which included 1,450 women, revealed that those with higher levels of glyphosate in urine samples collected during midpregnancy were more likely to go into spontaneous labor before 37 weeks than those with lower amounts of the herbicide.